Railway-signal



UNITED STATES PATENT OrFi-cn.

CHARLES WV. GRANT, CONCORD, MASSACHUSETTS, ASSIGNO R TO THE AMERICANELECTRIC TRAIN AND SWITCH SIGNAL COMPANY, OF BOS- TON, MASSACHUSETTS.

RAILWAY-SIGNAL.

SPECIFICATION forming part of Letters Patent No. 589,170, dated August31, 1897.

Application filed November 19, 1896. Serial No. 612,733. (No model.)

To all whom it may concern: Other section of track more or less distant.

Be it known that 1, CHARLES V. GRANT, a In operation theconstantly-energized pricitizen of the United States, residing atConmary coil carried by the locomotive and record, county of Middlesex,and State of Masceiving an alternating current from a gener- 5sachusetts, have invented certain new and ator located thereon will tendto induce secuseful Improvements in Railway-Signals, of ondary currentsin the track-coils; but such 5 5 which the following is a specification,refertendency will only become effective in the once being made to theaccompanying drawevent of the circuit of said track-coils being ings,whereinclosed by the presence of an interfering train to Figure 1 is adiagram representing the plan on the distant section, and in such eventthe of a road-bed prepared for use in connection secondary currents inthe track-coils will inwith my system. Fig. 2 illustrates diagramducetertiary currents in the signal-receiving matically a section of thesaid road-bed and a coil carried by the locomotive. In thismanlocomotive equipped with the apparatus rener any locomotive will beautomatically noti- I 5 quired to operate with the corresponding apfiedthrough its own coils and its own genparatus on the roadway. Fig. 3represents a erator of the presence of another locomotive, 6 5 truckhaving an induction-coil suspended train, or car within a specifieddistance ahead therefrom. Fig. 4 represents the coreupon of it. whichthe induction-coils are wound, and My invention also consists in certainde- 20 Fig; 5 illustrates the invention as applied to a tails ofconstruction hereinafter set forth,

single-track road. Fig. 6 illustrates the part and particularly incertain testing arrangeas applied to adrawbridge or turnout-switch.ments by which the condition of the train My invention is based upon theprinciple of apparatus may be constantly indicated and electromagneticinduction between certain any failure or disarragement be immediately 25stationary coils along the road-bed and cerdisclosed.

tain othercoils carried by the locomotive of a The advantage of mysystem lies princitrain. pally in the fact that there is no apparatusMore particularly I place along the roadalong the track containing anymoving parts, bed a series of coils provided with iron cores and thesystem, so far as the track is con- 3 and arranged in series in acircuit terminatcerned, depends only upon fixed coils and ing at the twoopposite and insulated rails of conductors, which when once properly inasection of track more or less remote whereon stalled are not liable toinjury by Weather 7 an interfering or obstructing train may be ortemperature or to disarrangement in operstanding or running. These coilsare aration. There are also no stationary batteries 35 ranged to receivecurrent, in the event of or generators along the track, and suchcurtheir circuit being closed by the presence of rent as is employed isderived from a lowthe interfering train aforesaid, from a confrequencyalternating-current dynamo of a stantly-energized coil carried by thelocomosimple type placed on the locomotive, while tive in a positionwhere it may actinductively the remaining part of the apparatus carried0 thereon. In the event of the said track-coils by the train is freefrom complications and being energized they in turn act inductively isunder the constant supervision of the en- 0 upon a secondcoil carried bythe locomotive gineer. It is also of a character not at all andconnected with a bell or other signaling liable to disarrangements ofany kind. device responsive to an alternating current. Referring to thedrawings, A A A repre- 4 5 In practice the track-coils will be groupedtosent three insulated sections of railway-rail,

, gether in a series, including those adjacent to and B B B representcorresponding sections 5 one section of track, and the terminalsof ofthe opposite rail. Between the two rails their circuit will beconnected, respectively, of each section on a uniform level I place a,to the two opposite and insulated rails of anseries .of coils C C C,which are preferably wound on rectangular iron frames of the form shownin Fig. 4, and I connect together in series all of the coils in any onesection. The two terminals of the coils thus grouped together areextended along the track and connected, respectively, to the rails ofanother section, more or less distant, preferably the second sectionahead. Thus in Fig. l the coils O U, &c., (shown in full lines as placedbetween the rails A and 13,) are connected in series and their terminalsconnected to the rails A and B of the next section but one in advance.Similarly the coils between sections A and B will be connected to therails of section A B If itis desired to work in both directions on asingle track, there will be required two sets of coils C C, &e., thecoils of one set alternating with those of the other set, and theterminals of one set connecting with rail-sections in advance and thoseof the other set with rail-sections in the rear. Thus, referring to Fig.5, there are shown between the rail-sections A B two series of coils OO, the, and C C C, &c., the former series connecting with therail-sections A and B and the lattersections with the rail-sections Aand B. \Vith the arrangement described it is obvious that in Fig. 1, forinstance, a train on rail-sections A B will close the circuit of coils CC, &c., between rail-sections A and B, while in Fig. 5 one setof coilswill have their circuit closed by a train on A B and the other by atrain on a set A 13. Moreover, I may arrange that any unusualcircumstancc-such as the opening of a drawbridge or the throwing of aturnout-switchin any section will operate to close a circuit between thetwo rails and thereby complete the circuit of the track-coils connectedwith said rail. Thus in Fig. 6, M represents a drawbridge inrailsections A B, and it is so arranged that when moved from its normalposition (shown in the drawings) it will release a spring-switch P andclose the circuit between rails A and B in which event an approachingtrain will receive a signal in the same manner as it would if the railsA and B were connected by a train standing or running thereon.

Referring to Fig. i, I have shown the trackcoils C O, &c., as laid inthe roadway ll ush with the upper surface of the ties D D, the centerone of the five coils being shown in section in order to illustrate theconstruction of the coil, which, as I have already stated, is woundabout a rectangular frame grooved on its periphery to receive the wire.A coil E of similar construction is carried on one part of thelocomotivefor instance, underneath the tender-being suspended directlyfrom the axles or any fixed point, as shown in Fig. 3, in order that itmay be held at an invariable distance away from, but in close proximityto, the track-coils C C. The trackcoils may be as numerous as desired,although their number will naturally be limited by the length of thecoil carried on the tender and the frequency with which it is desired toreceive indications from the section ahead. This coil E is connecteddirectly with an alternating-current generator on the locomotive, whichwill be constantly running and sending at all times an alternatingcurrent through the coil. A similar but smaller coil E will be carriedat a remote point of the lecomotive-for instance, directly underthepilot or forward track-so as to be free from the inductive influence ofthe primary coil E. This coil E will be suspended, just like E, at afixed distance from the track-coil C C, &c., and its line-circuit willinclude a bell G or other device responsive audibly to an alternatingcurrent. The circuit of coil E will be controlled by an ordinary switchH and the circuitof coil E by a similar switch I.

The operation of the apparatus thus described will be obvious. Thegenerator F will keep the coil E constantly energized by an alternatingcurrent, which in turn will induce secondary currents in the track-coilC C, &c., provided there is an interfering train in the neighborhood onthe section of track to the rails of which the coils C C are connected.\Vhen such an induced currentpasses in the coils O 0, they will actinductively to produce a tertiary current in the coil E that will serveto operate the bell G.

Referring again to Fig. 2, it will be observed that just above coil Eand in close proximity thereto is a similar but smaller coil N, having amagnet 0 included in its circuit, which circuit is controlled by aswitch J. The purpose of this coil is to serve as a continual test ongenerator F and primary coil E. So long as the normal currentis passingthrough the said generator and coil a secondary current will passthrough coil N and magnet O and maintain in its attracted position thearmature of the said magnet, which in turn controls a mechanical bell L.It": for any reason there is an interrupt-ion of the usual current inthe primary circuit, it will be followed by a cessation of currentin thesecondary circuit, and the magnet- 0 will hence release its armature,allowing the bell L to ring. I have also provided a switch K, by meansof which I can at anytime throw the coils E and E, the bell G, andgenerator E into a common circuit in series. I thus provide means fortesting the integrity of coil E and the opcrativeness of bell G at anytime.

In the position of switch K shown in the drawings the two circuits areindependent of each other; but if the switch be moved upward, so as tothrow the switch-arminto contact with the connected points R R,respectively, there will obviously be a series circuit provided throughthe several parts of the apparatus above described.

It is possible also to place one or more trackcoils in a local circuitalong the line for the purpose of signaling at crossings and at otherpoints where it is desired to give warning of an approachingtrain. InFig. 1 I have shown two sets of coils in section A 13 which areconnected with a local circuit including a bell S. V

1 I am awarethat it has been heretofore proposed to communicate with amoving train by means of a line-wire extending along the track andacting inductively upon a coil on a train. I have, however, ascertainedby experience that such a system is impracticable, at least foraudible-signaling purposes, and that it is essential to employ a seriesof coils capable of acting with considerable inductive strength uponeach other. A

What I claim as new, and desire to scour by Letters Patent, is

1. The combination in a railway signaling system of a series of coilslocated along a section of railway and having their terminals connectedto the track-rails of a neighboring section, a generator on the trainfor energizing the said coils by induction and a receiving-coilcarriedby the same train in proximity to the said series of track-coils andconnected with signal-receivin g apparatus on the train, substantiallyas and for the purpose set forth.

2. The combination in a railway signaling system of a series of coilsprovided with iron cores located along a section of railway and havingtheir terminals connected to the trackrails of a neighboring section, agenerator on the train for energizing the said coils by induction and areceiving-coil having an iron core carried by the same train inproximity to the said series of track-coils and connected withsignal-receiving apparatus on the train.

3. The combination in a railway signaling system of a series oftrack-coils having their terminals connected to the opposite insulatedrails of a neighboring section of the track, an

alternating-current generator carried by the train, a coil on the trainin the circuit of said generator carried at a point adjacent to thetrack-coils, so as to induce current therein, and a receiving-coil alsoon the train carried in a similar position and'provided withsignal-receiving devices, substantially as and for the purpose setforth.

4. The combination in a railway signaling system of three adjacentsections of track, the rails of each section being insulated from thoseof the other sections, a series of trackcoils arranged along'th'e firstof the said sections, two insulated line-wires connected to theterminals of said coils respectively and extending along the second orintermediate one of the said sections and connected respectively to theinsulated track-rails of the third or last one of the said sections, analternatingcurrent generator, an inducingcoil in the circuit of saidgenerator forming a primary coil for inducing an alternating current insaid track-coils, a receiving-coil carried by the train in proximity tothe said track-coils so as to receive a tertiary induced current in theevent of the circuit of said track-coils being closed, and signalingdevices on the train included in the circuit of said receiving-coil,substantially as and for the purpose set forth. 7

5. The combination in a railway signaling system of three adjacentsections of track, the rails of each section being insulated from thoseof the other sections, a plurality of track-coils connected in series ina common circuit and arranged in a single line adjacent to the first ofthe three sections aforesaid, two insulated conductors, one connected atthe beginning-of the, said first section to the terminal of the firstone of the said trackcoils and the other connected at the end of thesame section to the terminal of the last of the said track-coils, thetwo conductors extending from their said connection -points along andbeyond the second or intermediate one of the said threetrack-sectionsand connected respectively to the two insulated rails ofthe third or last one of the aforesaid three track-sections, analternating-current generator, an inducing-coil in the circuit of saidgenerator, forming a primary coil for inducing an alternating current insaid track-coils, a receiving-coil carried by the train in proximity tothe said track-coils, so as to receive a tertiary induced current in theevent of the circuit of said track-coils being closed, and signalingdevices on the train included in the circuit of said receiving-coil,substantially as and for the purpose set forth.

6. The combination in a railway signal system of a series oftrack-coils, an inducingcoil carried by the locomotive for generatingcurrent in said track-coils, an alternating-can rent generatorenergizing the said inducingcoils, a test-coil placed adjacent to thesaid inducing-coil, and indicating devices in the circuit of the saidtestcoils, substantially as and for the purpose set forth.

7. The combination of track-coils O C, &c., an ind ucing-coil E carriedby the train in proximity to the said track-coils, indicatingcoil N,generator F, normally energizing coil E, magnet O in the circuit of coilN, and a signaling device L controlled by said magnet O, substantiallyas and for the purpose set forth.

8. The combination with one or more caraxles of a railway-vehicle, of aninducingcoil suspended directly therefrom, a series of track-coilsarranged at or near the surface of the road-bed in proximityto the saidinducingcoil, a generator on the train for energizing the inducing-coiland a signaling device on the same train inductively operated by thesaid track-coil, substantially as and for the purpose set forth. I

9. The combination with an induced trackcircuit formed in part of thetrack-rail and in part by a conductor subject to inductive action, of agenerator on the train for supplying the said circuit with alternatingcurrent and a signaling-circuit on the same train energized inductivelyfrom the said track-circuit, substantially as and for the purpose setforth.

10. The combination in a railway signaling system of aninduction-circuit along the railway formed in part by insulated sectionsof track-rail, a drawbridge, or turnout, in said section, a switchcon-trolled by the said drawbridge, or turnout-switch, for closing thecircuit between the two rails in the event of the bridge, or turnout,being open, a generator on the train for inducing an alternating currentin said track-circuit and signaling devices on the same train operatedby the said induced current, substantially as and for the purpose setforth.

11. The combination in a railway signaling system of a railway-trackhaving its rails divided into three or more insulated sections, twoinduced circuits adjacent to one section and connected respectively withthe section in advance and in rear thereof, a generator on the train forinducing alternating currents section of railway, said track-coils beingincluded in a normally open circuit, an inducing-coil and areceiving-coil carried by the same train and arranged in the samelongitudinal line adjacent to the line of track-coils and means forclosing the track-coil circuit by the presence of a neighboring train.

13. The combination in a railway signaling system of a series of sectiontrack-coils on one section, a circuit for said coils controlled byatrain on a neighboring section, local trackcoils, a local circuittherefor, a signaling device in said local circuit and an inducing-coilfor energizing both the local track-coils and section track-coils,substantially as and for the purpose set forth.

In witness whereof I have hereunto set my hand this 16th day ofNovember, 1896.

CHARL IS \V. GRAN".

\Vitnesscs:

GEORGE T. CUNNINGHAM, ERNEST S. WILLIAMS.

